Hi Masami, On Mon, 2020-01-27 at 22:48 +0900, Masami Hiramatsu wrote: > Hi Tom, > > On Fri, 24 Jan 2020 16:56:11 -0600 > Tom Zanussi <zanussi@xxxxxxxxxx> wrote: > > > Hi, > > > > This is v3 of 'tracing: Add support for in-kernel dynamic event > > API', > > incorporating changes based on suggestions from Masami and Steven. > > > > - Rebased to trace/for-next > > > > - Regularized the entire API to use synth_event_*, > > kprobe_event_*, > > dynevent_*, and added some new macros and functions to make > > things > > more consistent > > > > - Introduced trace_array_find_get() and used it in > > trace_array_get_file() as suggested > > > > - Removed exports from dynevent_cmd functions that didn't need to > > be > > exported > > > > - Switched the param order of __kprobe_event_gen_cmd_start() to > > fix > > a problem found building with clang. Apparently varargs and > > implicit promotion of types like bool don't mix. Thanks to > > Nick > > Desaulniers for pointing that out. > > > > - Updated the documentation for all of the above > > > > Text from the v2 posting: > > > > This is v2 of the previous 'tracing: Add support for in-kernel > > synthetic event API', and is largely a rewrite based on suggestions > > from Masami to expand the scope to include other types of dynamic > > events such as kprobe events, in addition to the original sythetic > > event focus. > > Yeah, v3 basically looks good to me now :) > Please see my comment on [4/12]. Others are good. You can put my > Acked-by to those patches. > > Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> > except for [04/12]. > > Thank you! > OK, I'll add your acks for those. Thanks for all your comments! Tom > > > > The functionality of the original API remains available, though > > it's > > in a slightly different form due to the use of the new dynevent_cmd > > API it's now based on. The dynevent_cmd API provides a common > > dynamic > > event command generation capability that both the synthetic event > > API > > and the kprobe event API are now based on, and there are now test > > modules demonstrating both the synthetic event and kprobes APIs. > > > > A couple of the patches are snippets from Masami's 'tracing: > > bootconfig: Boot-time tracing and Extra boot config' series, and > > the > > patch implementing the dynevent_cmd API includes some of the > > spnprintf() generating code from that patchset. > > > > Because I used Masami's gen_*_cmd() naming suggestion for > > generating > > the commands, the previous patchset's generate_*() functions were > > renamed to trace_*() to avoid confusion, and probably is better > > naming > > anyway. > > > > An overview of the user-visible changes in comparison to v1: > > > > - create_synth_event() using an array of synth_desc_fields > > remains > > unchanged and works the same way as previously > > > > - gen_synth_cmd() takes a variable-length number of args which > > represent 'type field;' pairs. Using this with no field args > > basically replaces the previous 'create_empty_synth_event()' > > > > - The 'add_synth_field()' and 'add_synth_fields()' function from > > v1 > > are essentially the same except that they now take a > > dynevent_cmd > > instead of a synth_event pointer > > > > - The finalize_synth_event() from v1 is replaced by > > create_dynevent() in the new version. > > > > - The new v2 API includes some additional functions to initialize > > the dynevent_cmd - synth_dynevent_cmd() is used to do > > that. While > > it's an extra step, it makes it easier to do error handling. > > > > - There's a new trace_synth_event() function that traces a > > synthetic > > event using a variable-arg list of values. > > > > - The original generate_synth_event() using an array of values is > > now called trace_synth_event_array(). > > > > - For piecewise event tracing, the original > > generate_synth_event_start() and generate_synth_event_end() > > have > > now been renamed to trace_synth_event_end(). > > > > - add_next_synth_val() and add_synth_val() remain the same. > > > > - A similar API and test module demonstrating the API has been > > added > > for kprobe events > > > > - Both the synthetic events and kprobe events API is based on the > > dynevent_cmd API, newly added > > > > - The Documentation for all of the above has been updated > > > > Text from the orginal v1 posting: > > > > I've recently had several requests and suggestions from users to > > add > > support for the creation and generation of synthetic events from > > kernel code such as modules, and not just from the available > > command > > line commands. > > > > This patchset adds support for that. The first three patches add > > some > > minor preliminary setup, followed by the two main patches that add > > the > > ability to create and generate synthetic events from the > > kernel. The > > next patch adds a test module that demonstrates actual use of the > > API > > and verifies that it works as intended, followed by Documentation. > > > > Special thanks to Artem Bityutskiy, who worked with me over several > > iterations of the API, and who had many great suggestions on the > > details of the interface, and pointed out several problems with the > > code itself. > > > > The following changes since commit > > 659ded30272d67a04b3692f0bfa12263be20d790: > > > > trace/kprobe: Remove unused MAX_KPROBE_CMDLINE_SIZE (2020-01-22 > > 07:07:38 -0500) > > > > are available in the git repository at: > > > > git://git.kernel.org/pub/scm/linux/kernel/git/zanussi/linux- > > trace.git ftrace/synth-event-gen-v3 > > > > Tom Zanussi (12): > > tracing: Add trace_array_find/_get() to find instance trace > > arrays > > tracing: Add trace_get/put_event_file() > > tracing: Add synth_event_delete() > > tracing: Add dynamic event command creation interface > > tracing: Add synthetic event command generation functions > > tracing: Change trace_boot to use synth_event interface > > tracing: Add synth_event_trace() and related functions > > tracing: Add synth event generation test module > > tracing: Add kprobe event command generation functions > > tracing: Change trace_boot to use kprobe_event interface > > tracing: Add kprobe event command generation test module > > tracing: Documentation for in-kernel synthetic event API > > > > Documentation/trace/events.rst | 515 ++++++++++++++++++++ > > include/linux/trace_events.h | 124 +++++ > > kernel/trace/Kconfig | 25 + > > kernel/trace/Makefile | 2 + > > kernel/trace/kprobe_event_gen_test.c | 225 +++++++++ > > kernel/trace/synth_event_gen_test.c | 523 ++++++++++++++++++++ > > kernel/trace/trace.c | 43 +- > > kernel/trace/trace.h | 36 ++ > > kernel/trace/trace_boot.c | 66 ++- > > kernel/trace/trace_events.c | 325 +++++++++++++ > > kernel/trace/trace_events_hist.c | 896 > > ++++++++++++++++++++++++++++++++++- > > kernel/trace/trace_kprobe.c | 160 ++++++- > > 12 files changed, 2868 insertions(+), 72 deletions(-) > > create mode 100644 kernel/trace/kprobe_event_gen_test.c > > create mode 100644 kernel/trace/synth_event_gen_test.c > > > > -- > > 2.14.1 > > > >
